Systems and methods for wireless communication with asymmetric numbers of transmit and receive chains

ABSTRACT

This disclosure includes systems and methods for wireless communication using asymmetric transmit and receive chains. A device having a greater number of receive chains may be optimized for data reception and a device having a greater number of transmit chains may be optimized for data transmission. The relative ratio in performance between desired uplink and downlink performance may be adjusted accordingly. In one aspect, one wireless protocol may be used for communications to maintain a unidirectional link on another.

FIELD OF THE PRESENT DISCLOSURE

This disclosure generally relates to wireless communication systems andmore specifically to systems and methods for providing differing numbersof transmit and receive chains to achieve one or more desiredperformance characteristics.

BACKGROUND

Due to advances in technologies used for wireless communications, suchas those associated with a Wireless Local Area Network (WLAN) conformingto Institute for Electrical and Electronic Engineers (IEEE) 802.11protocols, wireless communications devices may feature multiple transmitand receive chains to provide increased bandwidth and achieve greaterthroughput. For example, the 802.11ad standard includes the capabilityfor devices to communicate in the 60 GHz frequency band over four, 2.16GHz-wide channels, delivering data rates of up to 7 Gbps. Otherstandards may also involve the use of multiple channels operating inother frequency bands, such as the 5 GHz band.

As will be appreciated, in order to provide multiple chains, a number ofelements may be required by each chain. For example, each chain mayrequire on-chip and off-chip components such as an antenna, an externalpower amplifier, a transmit-receive switch, a matching network, a lownoise amplifier and/or other related circuitry, resulting in significantcost, area, complexity and power demands. Conventional implementationsmay provide symmetric transmit and receive capabilities, such as byproviding all chains with the capability of transmitting and receiving.Accordingly, such devices typically exhibit performance associated withhaving equal numbers of transmit and receive chains.

However, there may be applications for which an intended use of awireless communications device makes it desirable to provide one or moreperformance characteristics associated with employing asymmetric numbersof transmit and receive chains. It may also be desirable to reducehardware complexity and cost while providing a level of performanceassociated with an intended use of the device. As will be detailed inthe materials below and the accompanying drawings, this disclosuresatisfies these and other goals.

SUMMARY

This disclosure involves systems for wireless communication, and may bedirected to a wireless communications device comprising a first wirelesslocal area network (WLAN) module that may use a first wireless protocolhaving m receive chains and n transmit chains, wherein m and n arenon-negative integers and m does not equal n. As desired, m and n may beselected to provide a desired performance characteristic.

In one aspect, n may be zero, such that the wireless communicationsdevice also includes a second WLAN module that may use a second wirelessprotocol and a transmission controller that may determine informationregarding first wireless protocol communications for transmission by thesecond WLAN module using the second wireless protocol. Further, theinformation regarding first wireless protocol communications indicatesdata successfully received by the first WLAN module. Also, the secondWLAN module may include an acknowledgement buffer, wherein thetransmission controller may store the information regarding firstwireless protocol communications in the acknowledgement buffer andwherein the second WLAN module may transmit the information from theacknowledgement buffer using the second wireless protocol. Additionally,the first wireless protocol may operate on a 60 GHz frequency band andwherein the second wireless protocol may be a legacy protocol operatingon a different frequency band.

In another aspect, wherein m may be zero and the wireless communicationsdevice may include a second WLAN module that may use a second wirelessprotocol and a reception controller that may determine informationregarding first wireless protocol communications from transmissionsreceived by the second WLAN module. As desired, the first WLAN modulemay retransmit data indicated as not being successfully received by theinformation regarding first wireless protocol communications.

This disclosure also includes methods for wireless communication usingan asymmetric number of transmit and receive chains. For example, asuitable method may involve providing a first wireless local areanetwork (WLAN) module that may use a first wireless protocol having mreceive chains and n transmit chains, wherein m and n are non-negativeintegers and m does not equal n and performing a communicationsoperation by receiving data using the m receive chains or transmittingdata using the n transmit chains. The numbers of transmit and receivechains m and n may be selected to provide a desired performancecharacteristic.

In one aspect, n may be zero and the method may include providing asecond WLAN module that may use a second wireless protocol, determininginformation regarding first wireless protocol communications andtransmitting the information regarding first wireless protocolcommunications using the second wireless protocol with the second WLANmodule. The information regarding first wireless protocol communicationsmay indicate data successfully received by the first WLAN module.Further, the second WLAN module may also have an acknowledgement buffer,such that the method includes storing the information regarding firstwireless protocol communications. In one embodiment, the first wirelessprotocol may operate on a 60 GHz frequency band and the second wirelessprotocol may be legacy protocol operating on a different frequency band.

In another aspect, m may be zero and the method may include providing asecond WLAN module that may use a second wireless protocol anddetermining information regarding first wireless protocol communicationsfrom transmissions received by the second WLAN module. Further, themethod may include retransmitting data indicated as not beingsuccessfully received by the information regarding first wirelessprotocol communications.

This disclosure also is directed to a non-transitory processor-readablestorage medium for a wireless communications device, theprocessor-readable storage medium having instructions thereon, whenexecuted by a processor that may cause the wireless communicationsdevice to enable a first wireless local area network (WLAN) module touse a first wireless protocol having m receive chains and n transmitchains, wherein m and n are non-negative integers and m does not equal nand to perform a communications operation such as receiving data usingthe m receive chains or transmitting data using the n transmit chains.

In one aspect, n may be zero and the instructions may cause the wirelesscommunications device to determine information regarding first wirelessprotocol communications and transmit the information regarding firstwireless protocol using a second wireless protocol with a second WLANmodule.

In another aspect, m may be zero and the instructions may cause thewireless communications device to determine information regarding firstwireless protocol communications from transmissions received by a secondWLAN module. Additionally, the instructions may cause the wirelesscommunications device to retransmit data indicated as not beingsuccessfully received by the information regarding first wirelessprotocol communications.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages will become apparent from the followingand more particular description of the preferred embodiments of thedisclosure, as illustrated in the accompanying drawings, and in whichlike referenced characters generally refer to the same parts or elementsthroughout the views, and in which:

FIG. 1 schematically depicts a wireless system involving a device havingasymmetric transmit and receive chains, according to one embodiment;

FIG. 2 schematically depicts functional blocks of a wirelesscommunications device, according to one embodiment;

FIG. 3 is a flowchart showing an exemplary routine for communicatingusing a device having asymmetric transmit and receive chains, accordingto one embodiment;

FIG. 4 schematically depicts functional blocks of a wirelesscommunications device configured for unidirectional reception, accordingto one embodiment;

FIG. 5 schematically depicts functional blocks of a wirelesscommunications device configured for unidirectional transmission,according to one embodiment; and

FIG. 6 is a flowchart showing an exemplary routine for unidirectionalwireless communication using a device having asymmetric transmit andreceive chains, according to one embodiment.

DETAILED DESCRIPTION

At the outset, it is to be understood that this disclosure is notlimited to particularly exemplified materials, architectures, routines,methods or structures as such may vary. Thus, although a number of suchoptions, similar or equivalent to those described herein, can be used inthe practice or embodiments of this disclosure, the preferred materialsand methods are described herein.

It is also to be understood that the terminology used herein is for thepurpose of describing particular embodiments of this disclosure only andis not intended to be limiting.

The detailed description set forth below in connection with the appendeddrawings is intended as a description of exemplary embodiments of thepresent disclosure and is not intended to represent the only exemplaryembodiments that may be practiced. The term “exemplary” used throughoutthis description means “serving as an example, instance, orillustration,” and should not necessarily be construed as preferred oradvantageous over other exemplary embodiments. The detailed descriptionincludes specific details for the purpose of providing a thoroughunderstanding of the exemplary embodiments of the specification. It willbe apparent to those skilled in the art that the exemplary embodimentsof the specification may be practiced without these specific details. Insome instances, well known structures and devices are shown in blockdiagram form in order to avoid obscuring the novelty of the exemplaryembodiments presented herein.

For purposes of convenience and clarity only, directional terms, such astop, bottom, left, right, up, down, over, above, below, beneath, rear,back, and front, may be used with respect to the accompanying drawingsor chip embodiments. These and similar directional terms should not beconstrued to limit the scope of the disclosure in any manner.

In this specification and in the claims, it will be understood that whenan element is referred to as being “connected to” or “coupled to”another element, it can be directly connected or coupled to the otherelement or intervening elements may be present. In contrast, when anelement is referred to as being “directly connected to” or “directlycoupled to” another element, there are no intervening elements present.

Some portions of the detailed descriptions which follow are presented interms of procedures, logic blocks, processing and other symbolicrepresentations of operations on data bits within a computer memory.These descriptions and representations are the means used by thoseskilled in the data processing arts to most effectively convey thesubstance of their work to others skilled in the art. In the presentapplication, a procedure, logic block, process, or the like, isconceived to be a self-consistent sequence of steps or instructionsleading to a desired result. The steps are those requiring physicalmanipulations of physical quantities. Usually, although not necessarily,these quantities take the form of electrical or magnetic signals capableof being stored, transferred, combined, compared, and otherwisemanipulated in a computer system.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. Unlessspecifically stated otherwise as apparent from the followingdiscussions, it is appreciated that throughout the present application,discussions utilizing the terms such as “accessing,” “receiving,”“sending,” “using,” “selecting,” “determining,” “normalizing,”“multiplying,” “averaging,” “monitoring,” “comparing,” “applying,”“updating,” “measuring,” “deriving” or the like, refer to the actionsand processes of a computer system, or similar electronic computingdevice, that manipulates and transforms data represented as physical(electronic) quantities within the computer system's registers andmemories into other data similarly represented as physical quantitieswithin the computer system memories or registers or other suchinformation storage, transmission or display devices.

Embodiments described herein may be discussed in the general context ofprocessor-executable instructions residing on some form ofprocessor-readable medium, such as program modules, executed by one ormore computers or other devices. Generally, program modules includeroutines, programs, objects, components, data structures, etc., thatperform particular tasks or implement particular abstract data types.The functionality of the program modules may be combined or distributedas desired in various embodiments.

In the figures, a single block may be described as performing a functionor functions; however, in actual practice, the function or functionsperformed by that block may be performed in a single component or acrossmultiple components, and/or may be performed using hardware, usingsoftware, or using a combination of hardware and software. To clearlyillustrate this interchangeability of hardware and software, variousillustrative components, blocks, modules, circuits, and steps have beendescribed above generally in terms of their functionality. Whether suchfunctionality is implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem. Skilled artisans may implement the described functionality invarying ways for each particular application, but such implementationdecisions should not be interpreted as causing a departure from thescope of the present disclosure. Also, the exemplary wirelesscommunications devices may include components other than those shown,including well-known components such as a processor, memory and thelike.

The techniques described herein may be implemented in hardware,software, firmware, or any combination thereof, unless specificallydescribed as being implemented in a specific manner. Any featuresdescribed as modules or components may also be implemented together inan integrated logic device or separately as discrete but interoperablelogic devices. If implemented in software, the techniques may berealized at least in part by a non-transitory processor-readable storagemedium comprising instructions that, when executed, performs one or moreof the methods described above. The non-transitory processor-readabledata storage medium may form part of a computer program product, whichmay include packaging materials.

The non-transitory processor-readable storage medium may comprise randomaccess memory (RAM) such as synchronous dynamic random access memory(SDRAM), read only memory (ROM), non-volatile random access memory(NVRAM), electrically erasable programmable read-only memory (EEPROM),FLASH memory, other known storage media, and the like. The techniquesadditionally, or alternatively, may be realized at least in part by aprocessor-readable communication medium that carries or communicatescode in the form of instructions or data structures and that can beaccessed, read, and/or executed by a computer or other processor.

The various illustrative logical blocks, modules, circuits andinstructions described in connection with the embodiments disclosedherein may be executed by one or more processors, such as one or moredigital signal processors (DSPs), general purpose microprocessors,application specific integrated circuits (ASICs), application specificinstruction set processors (ASIPs), field programmable gate arrays(FPGAs), or other equivalent integrated or discrete logic circuitry. Theterm “processor,” as used herein may refer to any of the foregoingstructure or any other structure suitable for implementation of thetechniques described herein. In addition, in some aspects, thefunctionality described herein may be provided within dedicated softwaremodules or hardware modules configured as described herein. Also, thetechniques could be fully implemented in one or more circuits or logicelements. A general purpose processor may be a microprocessor, but inthe alternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

Embodiments are described herein with regard to a wirelesscommunications device, which may include any suitable type of userequipment, such as a system, subscriber unit, subscriber station, mobilestation, mobile wireless terminal, mobile device, node, device, remotestation, remote terminal, terminal, wireless communication device,wireless communication apparatus, user agent, or other client devices.Further examples of a wireless communications device include mobiledevices such as a cellular telephone, cordless telephone, SessionInitiation Protocol (SIP) phone, smart phone, wireless local loop (WLL)station, personal digital assistant (PDA), laptop, handheldcommunication device, handheld computing device, satellite radio,wireless modem card and/or another processing device for communicatingover a wireless system. Moreover, embodiments may also be describedherein with regard to an access point (AP). An AP may be utilized forcommunicating with one or more wireless nodes and may be termed also becalled and exhibit functionality associated with a base station, node,Node B, evolved NodeB (eNB) or other suitable network entity. An APcommunicates over the air-interface with wireless terminals. Thecommunication may take place through one or more sectors. The AP may actas a router between the wireless terminal and the rest of the accessnetwork, which may include an Internet Protocol (IP) network, byconverting received air-interface frames to IP packets. The AP may alsocoordinate management of attributes for the air interface, and may alsobe the gateway between a wired network and the wireless network.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood by one having ordinaryskill in the art to which the disclosure pertains.

Finally, as used in this specification and the appended claims, thesingular forms “a, “an” and “the” include plural referents unless thecontent clearly dictates otherwise.

As indicated, this disclosure involves systems and methods for wirelesscommunication using asymmetric transmit and receive chains. To helpillustrate certain aspects, an exemplary WLAN communication system 100is depicted in FIG. 1. In this simplified example, wirelesscommunications device 102 is associated with access point (AP) 104 in aconventional infrastructure WLAN. The techniques of this disclosure mayalso be applied to any other suitable network role, includingcommunications with another device in a peer to peer network such asWiFi Direct™ or function as a software-enabled AP (softAP) serving oneor more clients. FIG. 1 schematically indicates communications that maybe exchanged between wireless communications device 102 and AP 104 usingan asymmetric number of transmit and receive chains, as viewed from theperspective of wireless communications device 102. For example, wirelesscommunications device 102 sends data over one transmit chain to generateuplink stream 106 and receives downlink streams 108 and 110 using twocorresponding receive chains.

As such, the configuration of wireless communications device 102 shownallows for the reception of data using two chains and the transmissionof data using one chain. This configuration may be desirable forapplications in which the device is primarily a sink for data. Underthese circumstances, it may be desirable to provide relatively greaterdownlink bandwidth to facilitate reception of data and to providerelatively reduced uplink bandwidth, which may still be sufficient forthe more modest transmission requirements, such as acknowledgementmessages. In one embodiment, wireless communications device 102 may beconfigured to employ four receive chains using an 802.11ad protocoloperating on the 60 GHz frequency band. Alternatively, a device mayemploy more transmit chains than receive chains if the device's primaryfunction is the transmission of data, such as in a multicastingapplication. Further, the ratio in performance between desired uplinkand downlink performance may be achieved directly by changing thenumbers of transmit and receive chains.

In some embodiments, transmit stream 106 and receive streams 108 and 110may be configured to employ the same frequency band, such as the 60 GHzband. In other embodiments, any desired combination of frequency bandsmay be employed. For example, transmit stream 106 and receive stream 108may employ a first frequency band, such as one of the 2.4 or 5 GHzbands, and receive stream 110 may employ a second frequency band, suchas the 60 GHz band. Accordingly, in some embodiments, no receive ortransmit chain may be provided in one of the frequency bands. Forexample, a device that is primarily intended to receive data may featureno transmit chains and one or more receive chains operating on the 60GHz band. Uplink communications associated with managing downlinkoperations or otherwise maintaining the link may include informationregarding communications using the wireless protocol associated with the60 GHz band, such as acknowledgements and other control information, maybe performed on the 2.4 GHz or 5 GHz frequency band. In this manner,downlink performance may take advantage of the increased throughputassociated with use of the 60 GHz band and any necessary uplinktransmissions may take place over a more power efficient frequency band.Furthermore, these techniques may be readily applied to wirelessprotocols operating on any other frequency bands as desired.

Further details are provided in the context of wireless communicationsdevice 200 embodying aspects of this disclosure as schematicallyillustrated in FIG. 2. Generally, wireless communications device 200 mayemploy an architecture in which the lower levels of the WLAN protocolstack are implemented in firmware and hardware modules of WLAN module202. WLAN module 202 may include digital baseband processor 204 forperforming operations at the media access control (MAC) layer to handleand process 802.11 frames of data including verification,acknowledgment, routing, formatting and other applicable functions.Digital baseband processor 204 may also perform operations at thephysical (PHY) layer, exchanging incoming and outgoing frames with theMAC layer by modulating and demodulating the frames according to therelevant 802.11 protocol.

In this embodiment, digital baseband processor 204 outputs an analogstream for transmission that if fed to the analog portion of a transmitchain, indicated by box 206. Components within the transmit chain mayinclude baseband filter (BBF) 208, to reduce noise resulting from thedigital-to-analog conversion process in digital baseband processor 204.Mixer block 210 may up-convert the analog signal to a desiredtransmission radio frequency (RF) using a suitable signal, such as froma local oscillator. Next, a sequence of amplifiers, such as driveramplifier (DA) 214 and an external power amplifier (PA) 216 may boostthe signal to an adequate level for transmission. The RF signal may thenbe coupled to antenna 218 for transmission through duplexer (Dux) 220.As desired, a switch or other equivalent element may be used. Dependingupon the architecture of wireless communications device 200, otherconventional circuit elements may be present in the transmit chain.

According to the techniques of this disclosure, RF signals may bereceived using an asymmetric number of receive chains. In thisembodiment, the analog portions of suitable receive chains are indicatedby box 222 and 224. As shown, the receive chain indicated by box 222 maybe configured to share antenna 218, such that the received RF signal isfed by duplexer 220. Generally, the received signal may be amplified bylow noise amplifier (LNA) 226, down-converted in frequency, such as tobaseband, by mixer 228 responsive to a suitable signal and thenprocessed by BBF 230 before being fed to digital baseband processor 204.After conversion to digital, the stream may be processed to recover thepayload. Likewise, the receive chain indicated by box 224 may alsoinclude LNA 232, mixer 234 and BBF 236 and may be coupled to antenna238. As with the transmit chain, the receive chains may also includeother or different conventional circuit elements. The transmit chainindicated by box 206 and the receive chain indicated by box 222 mayshare antenna 218 in this embodiment, although any suitable number ofantennas may be employed and/or shared by the transmit and receivechains using known techniques.

Further, wireless communications device 200 may also include host CPU240 configured to perform the various computations and operationsinvolved with the functioning of wireless communications device 200.Host CPU 240 is coupled to WLAN module 202 through bus 242, which may beimplemented as a peripheral component interconnect express (PCIe) bus, auniversal serial bus (USB), a universal asynchronousreceiver/transmitter (UART) serial bus, a suitable advancedmicrocontroller bus architecture (AMBA) interface, a serial digitalinput output (SDIO) bus, or other equivalent interface. Upper layers ofthe protocol stacks of the WLAN system may be implemented in software asDrivers 244 stored in memory 246 that may be accessed by host CPU 240over bus 242

Correspondingly, wireless communications device 200 may be seen toenable transmission of a single stream using one transmit chain and toenable reception of two streams using the receive chains. As describedabove, the use of asymmetric numbers of transmit and receive chainsallows wireless communications device 200 to be tailored to provide oneor more desired performance characteristics. In this example, the use oftwo receive chains provides relatively greater downlink bandwidth ascompared to uplink bandwidth and may be suited to applications in whichwireless communications device 200 is primarily a recipient of wirelessdata. By employing different numbers of transmit and receive chains,other performance characteristics may be emphasized as desired.

Further, by employing asymmetric numbers of transmit and receive chains,substantial economies of hardware, cost, complexity and powerconsumption may be realized. Notably, this implementation saves theresources represented by a second transmit chain, including a duplexeror other antenna switching mechanism, an amplifier chain, anupconverting mixer and associated local oscillator and a filter as wellas other circuit elements that may be used in the transmit chain. Inparticular, the power amplifier represents a significant savings in thecontext of the resource budget. As will be appreciated in the example ofwireless communications device 200, equivalent downlink performance maybe achieved as compared to a conventional architecture using symmetrictransmit and receive chains while avoiding the need to provide a secondtransmit chain. Further, omitting one or more receive chains compared tothe number of transmit chains may represent a savings of the associatedamplifiers, downconverting mixers, filters and related circuitry. Inother implementations, any desired balance between uplink and downlinkperformance may be achieved by adjusting the number of transmit chainsand the number of receive chains.

An example of the operation of a wireless communications deviceembodying aspects of this disclosure is represented by the flowchartdepicted in FIG. 3. As shown, a suitable routine may begin in 300 byestablishing a WLAN connection between a wireless communications devicehaving asymmetric numbers of transmit and receive chains and a remotedevice, which may also be configured to employ asymmetric transmit andreceive chains or may be conventionally configured as desired. Asindicated by 302, the wireless communications device may receivedownlink data from the remote device using m receive chains, wherein mis any suitable non-negative integer. Correspondingly, as indicated by304, the wireless communications device may transmit uplink data to theremote device using n transmit chains, wherein n is any suitablenon-negative integer not equal to m. As described above, any desiredrelation between downlink and uplink performance may be achieved byadjusting the ratio of m to n.

In a further aspect, providing asymmetric transmit and receive chainsmay include configuring a device to have either no transmit chains or noreceive chains for a first wireless protocol. In such implementations,any data traffic necessary to establish and maintain the communicationslink for the first wireless protocol may be exchanged using a secondwireless protocol. A suitable example of a wireless communicationsdevice having no transmit chain for a first wireless protocol isdepicted schematically in FIG. 4. As shown, wireless communicationsdevice 400 may employ an architecture in which the lower levels of theWLAN protocol stack are implemented in firmware and hardware of WLANmodule 402, which is configured to employ a first wireless protocol andmay have one or more receive chains only. In one embodiment, WLAN module402 may operate on the 60 GHz frequency band utilizing an 802.11adprotocol. WLAN module 402 may include a media access controller (MAC)404 that performs functions related to the handling and processing of802.11 frames of data including verification, acknowledgment, routing,formatting and the like. Incoming frames received from physical layer(PHY) 406, which as shown here includes the functions of demodulatingthe frames according to the relevant 802.11 protocol and the modulationand coding scheme (MCS) employed, which may be determined using anappropriate rate adaptation algorithm, for example. Analog receive chain408 provides the analog amplification, mixing and filtering processingas described above for RF signals received via antenna 410. Verifier 412assesses whether a transmission has been successfully received, such asby employing a cyclic redundancy check (CRC) on received frames and/orusing a checksum to ascertain which sub-frames of an aggregated framehave been received, using conventional techniques. Although depictedwith a single receive chain to simplify the illustration, wirelesscommunications device 400 may be configured with any suitable number ofreceive chains to provide the desired level of performance.

Wireless communications device 400 may also include another WLAN module414 configured to employ a different wireless protocol. For example,WLAN module 414 may use any suitable 802.11 a/b/g/n/ac protocol and mayoperate on the 2.4 GHz or 5 GHz frequency band. Similarly, WLAN module414 may include MAC 416 and PHY 418 to perform the operations describedabove. In this embodiment, WLAN module 414 provides duplex communicationas indicated by analog receive chain 420 and transmit chain 422 that arecoupled by duplexer 424 to antenna 426 to transmit and receive RFsignals. Other antenna coupling techniques such as a switch may be usedas desired. WLAN module 414 may also have acknowledgement (ACK) buffer428 to facilitate feedback regarding frames received by WLAN module 402as will be described below.

Wireless communications device 400 may also include host CPU 430configured to perform the various computations and operations involvedwith the functioning of wireless communications device 400, includingthe functionality associated with the upper layers of the WLAN protocolstack as noted above. Host CPU 430 is coupled to WLAN module 402 andWLAN module 414 through bus 432. Memory 434 may be coupled to bus 432 tostore transmitted and received information and processor-readableinstructions, such as software, related to the operation of host CPU430. In this implementation, reception (Rx) coordinator 436 may controlWLAN module 414 to provide acknowledgment of data received using WLANmodule 402 and other information regarding first wireless protocolcommunications as described below. In one alternative embodiment, thefunctionality of Rx coordinator 436 may be implemented at the MAC layerof either or both of WLAN modules 402 and 414. In such an embodiment, ahardware interconnect 438 (indicated as a dashed line as an optionalfeature) or equivalent circuitry may provide communication regarding thestatus of frames between the WLAN modules. The use of hardwareinterconnect 438 may facilitate satisfying any timing requirementsregarding the acknowledgement of received frames that may be imposed bythe wireless protocol used by WLAN module 402.

In the depicted embodiment, WLAN module 402 is coupled to antenna 410and WLAN module 414 is coupled to antenna 426. As desired and dependingupon other wireless protocols employed, one or more antennas may beshared between WLAN modules or circuitry configured to employ otherwireless communication protocols using switching techniques known in theart. Likewise, some or all elements of the respective WLAN modules maybe co-located on a common system (e.g., on the same circuit board or ondistinct circuit boards within the same system, or may be embedded onthe same integrated circuit as in a system on a chip (SoC)implementation).

Accordingly, wireless communications device 400 may receiveunidirectional data over WLAN module 402 while providing the control andmanagement communication necessary to maintain the first wirelessprotocol link using WLAN module 414. Wireless communications device 400may receive transmissions from a suitably configured device, such aswireless communications device 500 as depicted in FIG. 5. As shown,wireless communications device 500 may have a similar design, includingWLAN module 502 employing the same wireless protocol as WLAN module 402.WLAN module 502 correspondingly may have MAC 504 and PHY 506 to generateanalog transmit chain 508, which is coupled to antenna 510. In thisembodiment, wireless communications device 500 has asymmetrical transmitand receive chains in the form of one transmit chain and no receivechains. Although a single transmit chain is shown for clarity, anydesired number of transmit chains may be used. In one aspect, the numberof transmit chains may be selected to correspond to the number ofreceive chains provided by the intended recipient. Further, in otherembodiments, any desired number of receive chains may also be employed,either in a conventional, symmetrical relationship to the number oftransmit chains or an asymmetrical number according to the techniques ofthis disclosure. WLAN module 502 may also include transmission (Tx)buffer 512 to store frames or aggregated frames for delivery. As will bedescribed below, frames or sub-frames that were not successfullyreceived by wireless communications device 400 may be transferred to Txretry buffer 514 for another delivery attempt.

In a similar manner to wireless communications device 400, wirelesscommunications device 500 may also include WLAN module 516 configured toemploy the wireless protocol used by WLAN module 414. As such, WLANmodule 516 may also include MAC 518 and PHY 520 to perform theoperations described above with respect to analog receive chain 522 andtransmit chain 524 that are coupled by duplexer 526, or other suitableswitching means, to antenna 528. WLAN module 516 may also have ACKcontroller 530 to receive acknowledgments sent by wirelesscommunications device 400 regarding the reception of frames orsub-frames sent by WLAN module 502.

Also similarly, wireless communications device 500 may include host CPU532 coupled to WLAN module 502 and WLAN module 516 through bus 534.Memory 536 may be coupled to bus 534 to store transmitted and receivedinformation and processor-readable instructions, such as software,related to operation of host CPU 532. Here, transmission coordinator 538may process information from ACK controller 530 to determine whichframes or sub-frames transmitted by WLAN module 502 were notsuccessfully received by wireless communications device 400. In turn, Txcoordinator 538 may populate Tx retry buffer 514 with data that was notsuccessfully received. In an alternative embodiment, the functionalityof Tx coordinator 538 may be implemented at the MAC layer of either orboth of WLAN modules 502 and 516, and may employ hardware interconnect540 (indicated as a dashed line as an optional feature) to providecommunication regarding the status of frames between the WLAN modules.

Although in the embodiments shown in FIGS. 4 and 5 reception coordinator436 is depicted as software routines stored in memory 434, transmissioncoordinator 538 is depicted in memory 536 and verifier 412 is depictedas being implemented in firmware at the MAC layer, these functionalitiesmay be achieved using any desired combination of firmware, hardware orsoftware at suitable locations in the architecture of the respectivewireless communications devices.

Accordingly, wireless communications device 400 and wirelesscommunications device 500 may be configured to perform unidirectionaldelivery of information using a first wireless protocol and to performany communications associated with establishing and maintaining thefirst wireless protocol link using a second wireless protocol. Thecommunications associated with establishing and maintaining the firstwireless protocol link may include acknowledgements, management andcontrol messages, and other information regarding first wirelessprotocol communications. In one aspect, the first wireless protocol mayachieve one or more desired performance characteristics in relation tothe second wireless protocol, such as improved throughput, bandwidth orthe like. For example, the first wireless protocol may operate on the 60GHz frequency band using an 802.11ad protocol to achieve a relativelyhigh transfer rate and the second wireless protocol may be a legacyprotocol, such as any suitable 802.11a/b/g/n/ac protocol operating onthe 2.4 GHz or 5 GHz frequency bands, and may represent a more efficientprotocol with regard to the amount of information associated withestablishing and maintaining the communications link over the firstwireless protocol. To help illustrate aspects regarding the operation ofwireless communications device 400 to receive data transmitted bywireless communications device 500 using the first wireless protocol, arepresentative routine is depicted in the flowchart of FIG. 6.

Beginning with 600, wireless communications device 400 and wirelesscommunications device 500 may establish a communications link with thesecond wireless protocol, using WLAN module 414 and WLAN module 516respectively. In 602, the devices may advertise capabilities regardingcommunications using the first wireless protocol and negotiate anynecessary parameters. For example, wireless communications device 400may advertise the reception capabilities associated with WLAN module402. Upon determination of the ability of wireless communications device400 to receive communications using the first wireless protocol,wireless communications device 500 may allocate any desired amount ofsubsequent downlink data for transmission with WLAN module 502, storingsuch data in Tx buffer 512. Correspondingly, in 604, wirelesscommunications device 500 may transmit one or more frames or aggregateframes destined for wireless communications device 400 using WLAN module502. In 606, the one or more frames or aggregate frames may be receivedby WLAN module 402 and checked for accuracy using verifier 412. Rxcoordinator 436 then may send information regarding any successfullyreceived frames to ACK buffer 428 in 608. Wireless communications device400 may transmit information from ACK buffer 428 to wirelesscommunications device 500 using WLAN module 414 in 610. As desired, ACKbuffer 428 may be associated with an elevated priority to facilitateproviding feedback to wireless communications device 500 regardingsuccessfully received transmissions in a timely manner. The receivedacknowledgement information may be processed by ACK controller 530 atwireless communications device 500 to identify the one or more frames orsub-frames transmitted by WLAN module 502 that have successfully beenreceived by wireless communications device 400 in 612. In response, Txcoordinator 538 may populate Tx retry buffer 514 with any transmittedframes or sub-frames that were not acknowledged, so that they may besubsequently retransmitted as indicated by 614.

Using these techniques, ACKs, or block acknowledgements (BAs), may becommunicated to WLAN module 502 using information exchanged between WLANmodule 414 and WLAN module 516. Depending upon the nature of thedownlink data being received, it may also be desirable for wirelesscommunications device 400 to transmit information regarding transmissioncontrol protocol (TCP) or internet protocol (IP) data, such as TCP ACKs,upper layer control traffic, or the like, to wireless communicationsdevice 500. Accordingly, the network layer, implemented in memory 434for example, of wireless communications device 400 may be configured todirect any outgoing traffic to ACK buffer 428 for transmission by WLANmodule 414. Further, it may be desirable to modify the first wirelessprotocol as necessary to accommodate any additional latency that may beassociated with transmitting acknowledgement information using thesecond wireless protocol.

Described herein are presently preferred embodiments. However, oneskilled in the art that pertains to the present embodiments willunderstand that the principles of this disclosure can be extended easilywith appropriate modifications to other applications.

What is claimed is:
 1. A wireless communications device comprising: afirst wireless local area network (WLAN) module configured tocommunicate using a first wireless protocol, the first WLAN modulehaving at least a number (m) of receive chains and no transmit chains,wherein m is a fixed non-negative integer; a transmission controllerconfigured to determine information regarding communications receivedaccording to the first wireless protocol; and a second WLAN moduleconfigured to transmit the information using a second wireless protocol.2. The wireless communications device of claim 1, wherein m isconfigured to provide a desired performance characteristic.
 3. Thewireless communications device of claim 1, wherein the informationindicates data successfully received by the first WLAN module.
 4. Thewireless communications device of claim 3, wherein the information isstored in an acknowledgement buffer, and wherein the second WLAN moduleis further configured to transmit the information from theacknowledgement buffer.
 5. The wireless communications device of claim1, wherein the first wireless protocol operates on a 60 GHz frequencyband and wherein the second wireless protocol is a legacy protocoloperating on a different frequency band.
 6. A method for wirelesscommunications by a wireless communications device, comprising:operating a first wireless local area network (WLAN) module tocommunicate using a first wireless protocol, the first WLAN modulehaving at least a number (m) of receive chains and no transmit chains,wherein m is a fixed non-negative integer; determining informationregarding communications received according to the first wirelessprotocol; and operating a second WLAN module to transmit the informationusing a second wireless protocol.
 7. The method of claim 6, wherein m isconfigured to provide a desired performance characteristic.
 8. Themethod of claim 6, wherein the information indicates data successfullyreceived by the first WLAN module.
 9. The method of claim 8, furthercomprising storing the information in an acknowledgement buffer.
 10. Themethod of claim 6, wherein the first wireless protocol operates on a 60GHz frequency band and wherein the second wireless protocol is a legacyprotocol operating on a different frequency band.
 11. A non-transitoryprocessor-readable medium storing instructions that, when executed by aprocessor of a wireless communications device, causes the wirelesscommunications device to: operate a first wireless local area network(WLAN) module to communicate using a first wireless protocol, the firstWLAN module having at least a number (m) of receive chains and notransmit chains, wherein m is a fixed non-negative integer; determineinformation regarding communications received according to the firstwireless protocol; and operate a second WLAN module to transmit theinformation using a second wireless protocol.
 12. A wirelesscommunications device comprising: a first wireless local area network(WLAN) module configured to communicate using a first wireless protocol,the first WLAN module having at least a number (n) of transmit chainsand no receive chains, wherein n is a fixed non-negative integer; asecond WLAN module configured to communicate using a second wirelessprotocol; and a reception controller configured to determine informationregarding communications transmitted according to the first wirelessprotocol based on communications received via the second WLAN module.13. The wireless communications device of claim 12, wherein the firstWLAN module is configured to retransmit data indicated as not beingsuccessfully received based on the information.
 14. A method forwireless communications by a wireless communications device, comprising:operating a first wireless local area network (WLAN) module tocommunicate using a first wireless protocol, the first WLAN modulehaving at least a number (n) of transmit chains and no transmit chains,wherein n is a fixed non-negative integer; operating a second WLANmodule to communicate using a second wireless protocol; and determininginformation regarding communications transmitted according to the firstwireless protocol based on communications received via the second WLANmodule.
 15. The method of claim 14, further comprising retransmittingdata indicated as not being successfully received based on theinformation.
 16. A non-transitory processor-readable medium storinginstructions that, when executed by a processor of a wirelesscommunications device, causes the wireless communications device to:operate a first wireless local area network (WLAN) module to communicateusing a first wireless protocol, the first WLAN module having at least anumber (n) of transmit chains and no receive chains, wherein n is afixed non-negative integer; operate a second WLAN module to communicateusing a second wireless protocol; and determine information regardingcommunications transmitted according to the first wireless protocolbased on communications received via the second WLAN module.
 17. Thenon-transitory processor-readable medium of claim 16, wherein executionof the instructions further causes the wireless communications device toretransmit data indicated as not being successfully received based onthe information.